Single-Component White Emissive Organic–Inorganic Hybrid Copper Halide Composite Films for Remote UV-pumped White Light-Emitting Diodes with High Color Rendering Index

Lead-free organic–inorganic metal halides (OIMHs) are highly desirable owing to their remarkable properties including low toxicity, structural diversity, high stability, and solution processability. Nevertheless, the development of their single-component white emissive films remains a formidable challenge for remote white light-emitting diodes (WLEDs) application. In this work, (C₁₆H₃₆N)₂Cu₂I₄/polyvinylidene fluoride (PVDF) white emissive composite film is successfully fabricated through an in situ solvent evaporation crystallization process at room temperature. The elemental analysis and bonding between (C₁₆H₃₆N)₂Cu₂I₄ and PVDF are demonstrated by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) measurements. In addition, this composite film exhibits a broadband white emission with two peaks. Notably, the best photoluminescence quantum yields (PLQYs) of the PVDF based composite film reaches an impressive 96.7%. A (C₁₆H₃₆N)₂Cu₂I₄/PVDF based remote UV-pumped WLEDs with an impressive color rendering index of 95.5 is realized. Finally, the in situ fabrication method is expanded to fabricate (C₁₆H₃₆N)₂Cu₂I₄/polyacrylonitrile (PAN) composite films, and we further realized their single component remote WLEDs.